Ball mill with risers on liners to throw balls and oversize material towards feed end of mill and to progress smaller balls and fine material towards discharge end of mill



Aprll 24, 1956 A. c. DAMAN 2,743,060

BALL MILL WITH RISERS ON LINERS TO THROW BALLS AND OVERSIZE MATERIALTOWARDS FEED END OF MILL AND TO PROGRESS SMALLER BALLS AND FINE MATERIALTOWARDS DISCHARGE END OF MILL Filed Nov. 12, 1954 2 Sheetshee l L Q A. Vmm v B w ow mm P /n J 1 mm E E o 5 on R om/ fiow ow Him}...

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W q rl wl r wmm April 24, 1956 A c DAMAN 2,743,060

BALL MILL WITH RISERS ON LINERS TO THROW BALLS AND OVERSIZE MATERIALTOWARDS FEED END OF MILL AND TO PROGRESS SMALLER BALLS AND FINE MATERIALTOWARDS DISCHARGE END OF MILL Filed NOV. 12, 1954 2 Sheets-Sheet 2 j lG.- 4

IN I 'EN'IOR.

Arthur C. Damon ATTORNEYS BALL MILL WITH RISERS ON LINERS'TO THROW BALLSAND OVERSIZE MATERIAL TOWARDS FEED END OF MILL AND 'TO PROGRESS SMALLERBALLS AND FINE MATERIAL TO- WARDS DISCHARGE END 'OF MILL Arthur C.Daman, Denver, C610, assignor to Mining Process and Patent Company,Denver, Colo., a corporation of Delaware I Application November 12,1954, Serial No. 468,28

8 Claims. c1..z 41--1s3 .sizefeed material, toward the feed end of themill while permitting the progressive movement of fine material andsmaller balls through a series of restricted passages to the dischargeend of the mill. The improved liner arrangement includes a plurality oflifter members which may be varied in their spacing on the liner memberto provide a predetermined size opening between the members for thepassage of fine material. The lifter members are arranged andproportioned to protect the bolt holes in the liner section. Thearrangement and shaping of the liner sections and lifter members causesa crisscross counter fiow action of the material and the balls withinthe These and other objects and advantages may be more readilyascertained by referring to the following description and appendeddrawings in which:

Fig. 1 is a vertical longitudinal section, through a ball mill accordingto the present invention; 7 I

Fig. 2 is a fragmentary detail of the lifter members illus trating thecrisscross arrangement of the ball and the material;

Fig. 3 is a fragmentary cross sectional view of a portion of the shelland liner arrangement illustrating thelifters and the arrangementthereof in relation to the rotation of the drum; and

Fig. 4 is an elevational view of a litter according to'the arrangementillustrating the height of various portions of the lifter above theliner.

Referring to Fig. 1 of the drawings, and-11 represent, respectively,concrete mill beds or foundations for a ball mill at the feed anddischarge end thereof. A ball mill feed'head -12 has its hub 13journalledfor rotation in a bearing 14. The discharge head 15 hasits'hub 16 journalled for rotation in a bearing17. A ring gear 18 issecured to the discharge end 15, and power is applied thereto forrotating or operating the grinding mill; r

- A shell 19 is secured to the heads 12 and 15, forming the drum portionof the ball mill. I A sectioned liner 20 is secured to the shell 19 tocomplete'the main. portion of the assembly. A feed scoop member 21 feedsa frusto-conical sleeve 22, located within the hub 13, and which is-incommunication wth the interior of the mill. Material to be ground andgrinding balls are fed by the scoop member through the sleeve into themill. The end of ,the mill, adjacent the-head 12, is provided with anend liner'20a having a central opening 23 providing communication fromthe sleeve 22 to the interior of the mill.

. The discharge end of the mill'is provided with a liner 20b, abuttingthe discharge head 15, which is provided 2,743,060 ra m a Apr. 24, 1956ice tional in ball mills, and the assembly of the conventional v partsis'more ,or less standard practice.

In accordance with the present invention, .the liner. sections or plates20 are provided with a plurality of main lifter or riser members spacedapart, in the central portion of the ball mill. Feed end lifters orrisers 31 are provided at the feed end of the ball mill, and dischargeend lifters or risers 32 are provided at the discharge end there: of.'The lifters 30 are generally of the shape of rectangular hooks. Thelifter 30 comprises a central sloping section 33,. which issubstantially longitudinally aligned with the drum, a tapered tail orlong leg portion 34, which is extended at an angle to the longitudinallyaligned sections 33, and a head or short leg portion 35 which is,likewise,

set at an angle to the longitudinally aligned sections 33.-

. A riser 30is positioned so as to be in front of eachbolt hole 28, inrelation to the rotation of the ball The riser 31 is constructedsimilarly to the riser 30, and it includes a central sloping portion '36that extends longitudinally along the shell of the liner, a tapered longleg portion 37 extending from the longitudinal portion at an anglethereto along the shell, and a head portion 38 which extends at an anglefrom the section 36, on the opposite side of the tapered section 37. Thelong leg 37 is angularly extended from the portion 36 away from thedirection, of rotation, but the short leg 38 extends angularly into thedirection of rotation. The short leg 38 tends to keep grindi ing ballsand material away from the liner 20a. Theriser 32 comprises a portion 39that extends longitudinally along the liner of the ball mill, whichportion is tapered from the feed end toward the discharge end. A headend 40-is'sewith a central opening 24. A'sleeve member'25 is secured vwithin the opening 24. The central opening 24 communi cured to thelongitudinal section 39 and itextends at an angle downwardly from thelongitudinal section, The upper surface 39a of the riser 32 slopes fromthe fced to the discharge end thereof. This riser 32 tends to throwground material toward the discharge and the balls toward the feed end.a v

As illustrated in detail in Fig. 2, the risers provide passages forlongitudinal distribution of material and the balls in the ball mill.The short leg 35 whichis of greater thickness than the long leg 34 tendsto throw balls Which are of a larger diameter than the width of thepassage between the short leg 35 and the next adjacent long leg ,34,toward the feed end. Material which is smaller than the distance betweenthe short leg and its next adjacent" long leg tends to move toward thedischarge end. For example, a ball 50 which has a diameter greater thanth'edis'tance between the long leg 34 and its next adjacent shortleg-35, is thrown back toward the feed end over surface 340, asindicated by the arrow, where the movement of the riser 30 is upward, asindicated by arrows near the riser. Small particles 51 pass'through thepas: sage between the short leg 35 and the long'leg 34 so that theyareactually moved toward the discharge endotthe ball mill. Material ofsmall size and small balls, therefore, move from the feed end to thedischarge etid of the mill. The risers are spaced apart to provide therestrictive passage therebetween, and the of the passages may be changedfrom the feed to the discharge end .to perform various types .of,grinding. The width of the passages may, for example, be progressivelynarrowed 'fromthe feed to the discharge end. The sh'ortjl'eg of therisers tends to throw large balls back to the feed end of the mill,while the restrictive passage permitssmall material tomove toward thedischarge end of the mill. If it is'desired, in the charging of the ballmill, small balls may be introduced at the discharge end and "the largeballs may be introduced at the feed end, although it is possible andsatisfactory to introduce .both small and largeballs at the feed end ofthe mill along with material to be ground. In either-case, the largeballs'tend to stay toward the feed end .of themill while the smallerballs work their way to the discharge of the mill. Oversize materialtends to travel toward the feed end, similarly to the balls, :and thesmaller material tends 'to travel toward the discharge end. Thus, acrisscross, counterflow movement of the finer material and finer ballsis achievedin relation to the larger balls and larger material to beground.

The plates or sections 20 are provided with longitudinal ridges 41 atone end thereof to aid the grinding action'of the balls on thematerialin the mill. The ridges increase the height of the cascade and increasesgrinding eificiency.

"While the risers have been shown of a particular shape, that is,-with-one short leg and one long leg, it is obvious that by changing theconfiguration of the risers, various grinding actions may be obtainedand various types of grinding may be accomplished. Further, the changeof spacing of the "risers in .the ball mill will provide variousgrinding actions. The risers 31 tend to keep the balls and largematerial away from the liner 7'0aon the end of the ball mill, likewisethe risers 32 aid in maintaining the balls away from the liner end 20bon the discharge end. It is to be understood further that the linersections or plates '20 together'withthe reflective flanges 41 securedthereon, the lifter members and the angle parts may be formed from anysuitable and desirable material, for example, ferrous metal, steel,rubber, or the like.

While the "invention has been illustrated with respect to a specificembodiment, there is no intent to limit the invention to the particulardetails so illustrated, except insofaras set forth in the followingclaims.

I claim:

1. Asectional liner for crushing mills utilizing balls orthe like as 'acrushing medium comprising a plurality of liner members mounted on theface of said mill, and being shapedfor cooperative positioning withinsaid mill to shield the inner surface of the mill from destructiveabrasion, raised flanges at spaced positions on the inner materialcrushing surfaces of said members, raised porlions extending from theterminal ends of said flanges toward but out of contact with adjacentportions, one of said raised portions being at least about as high assaid flange and extending outwardly at an angle thereto, the other saidraised portion being tapered downwardly and extending outwardly from theopposite end of said flanges, whereby to provide helically alignedpassages therebetwecn,- said passages being of 'sufiicient dimension toprovide 'for the free iiow of small sized particles toward the dischargeend of said mill, while preventing the passage of crushing balls andparticles larger than the dimensions of said passage through the sametoward the feed end.

2. Structure in accordance with claim 1 wherein the liner members,flanges and raised portions are formed of ferrous metal.

3. Structure in accordance with claim 1 wherein the linerlmembers,flanges and raised portions are formed unitarily of steel.

4. Structure in accordance with claim 1 wherein the *liner' members,flanges and "raised portions are formed selectively of rubber.

5. A sectional liner for rotary crushing mills utilizing balls or thelike as a crushing medium comprising a plurality of curved liner membersmounted on the inner surface of said milLsaid members being shaped forcooperative positioning within said mill to shield the inner surface ofthe min from destructive abrasion, raised flanges on the inner materialcrushing surfaces of said members at spaced positions, raised portionsextending from the terminal ends of said flanges toward but out ofcontact with adjacent portions, said passages being of sufficientdimension to provide for the free flow of small sized particlestherethrough toward the discharge end of said mill while preventing thepassage of crushing balls and particles larger than the dimensions ofsaid passage and through the same toward the feed end of the mill,saiddincr members being provided with openings therethrough in positionsadjacent said flanges and raised portions onthe side of said flangesopposite the direction of rotation ofsaid mill, and fastening means forinsertion'throug'h said openings for securing said liner members to theinner surface of said mill.

6. A sectional 'liner for crushing mills utilizing balls or the like asa crushing medium comprising a plurality of curved liner members mountedon the inner surface of said mill, said members being shaped forcooperative positioning within said mill to shield the inner surface ofthe mill from destructive abrasion, raised substantially V-shapedflanges on the inner material crushing surfaces of said liner members atspaced positions arranged to align adjacent flanges in a plurality ofdirections, the legs of said fiangescxtending towardbut out of contactwith the legs of adjacent flanges to provide helically aligned passagestherebetween, said passages being of suflicient dimension to provide forthe free flow of small sized particles therethrough toward the dischargeend of said mill while preventing the passage of crnshingballs andparticles larger than said dimensions and throwing the same toward thefeed end of the mill, and said flanges being spaced circumferentiallyapart a distance .circumferentially suflicient to allow thecrushingball'sto come into contact with the inner crushing surface ofsaidliher members to effect particle size reduction of the materialcharged into the mill.

"7. A sectional liner for rotary crushing mills utilizing balls orthelike as a crushing medium comprising a plurality of curved liner membersmounted in said mill, said members being shaped for cooperativepositioning within said mill to shield the inner surface of the millfrom destructive abrasion, raised v shaped flanges on the inner materialcrushing surfaces of said liner members at spaced positions arranged toalign adjacent flanges in two directions, said flanges being taperedfrom one terminal end to the other end thereof, the terminal ends ofsaid flanges extending toward but out of contact with the adjacentflanges to provide 'helically arranged passages therebetWCBIlySfildpassages being-of sufficient dimension to provide for the free flow ofsmall sized particles therethrough toward the discharge end of said millWhile preventing the passage of-crushing bal-ls and particles largerthan said dimension and throwing the same toward the feed end of saidmill, and saidfianges being spaced circumferentially'apart a distancesufficient'to allow the crushing balls to come into contact with theinner crushing surface of said members to cause particle size reductionof the material charged into the'mill.

8. A sectional liner for rotary crushing mills utilizing balls orthelike as a crushing medium comprising a plurality of curved linermembers mounted in said mill and shaped for cooperative positioningwithin said mill to shidld-thelinner surface of the mill fromdestructive abrasion,.raised V-shapedjianges on the inner materialcrushing surfaces of said liner members at spaced positions arranged toalign adjacent flanges in a plurality of direc- 5 tions, the terminalends of said flanges extending toward but out of contact with theadjacent flanges to provide helically arranged passages therebetween,said passages being of suflicient dimension to provide for the free flowof small sized particles therethrough toward the discharge end of saidmill while preventing the passage of crushing balls and particles largerthan the dimensions of said passages, a projecting rib on the leadingedge of said liner members out of contact with said flanges, saidflanges and said projecting ribs being spaced apart each from each adistance sufiicient to allow the crushingballs to come into contact withthe inner crushing surface of said members to cause further particlesize reduction of the materials 5 charged into the mill.

References Cited in the file of this patent FOREIGN PATENTS 475,551France Mar. 8, 1915

